Powered disk and drum sanders are commonly known and used for sanding floors and other surface areas. Floor sanders designed specifically for floor surface applications are of the motorized drum sander type. Traditionally, the leading and trailing edges of a sheet of sand paper are secured within a slot on the drum by a paper edge gripping mechanism in order to hold the sand paper on the drum. There are other methods of doing it; such having three screws securing a bar that captures the butting edges of the sheet. The screws are known to come loose and scrap the floor. All of these methods rely on the butt joint as the point of security, the point where the sheet is attached to the drum. The remaining surface area of the sheet is wrapped around the drum but is not secured to the drum body or surface.
There are other methods of mounting disposable sanding material to sanders. One method employs a loop or belt of sand paper that must be slid over one end of the drum, where the drum is supported on the sander at its other end by a heavy bearing. The belts may be used in combination with drums of retractable diameters which are then expanded to hold the belt in place. The drum designs are complex, and often don't perform well due to the expansion mechanisms, causing excessive “chatter” in use and leaving undesirable marks on the sanded floor surface.
Other types of sanders such as hand held or bench mounted rotating disk sanders (as opposed to drum sanders) have been known to try to use hook and loop fastener materials such as Velcro® brand material to secure the sand paper to the flexible sanding pad. However, the load and load distribution are markedly different for a disk sander than for a drum. There is not the continuous weight of a floor sander bearing on the contact interface causing increased pressure and temperature at the sandpaper to pad attachment interface, there is no centrifugal force normal to the attachment interface attempting to dislodge the sandpaper from the pad, and there is no paper joint on the sanding disk exposed to the leading edge lip peeling action of the passage of sandpaper over the surface or floor being sanded. The contact area or pressure print of a rotating sanding disk to the floor is typically constrained to less than one side of the disk area, and so excludes the region of the point of attachment, at the center of the disk.
For all drum type floor sanders, the weight of the machine combined with the rotating drum works to remove material from the floor surface. In finishing or re-finishing operations, some skill is required to achieve a satisfactory result. As is well known, the sanding sheets are consumed by use and must be replaced frequently. There is some user resistance to the effort and attention to detail that is required in order to install new sanding blanks with the necessary precision on the drum; so better and easier mounting methods are sought.
It is unknown to this Applicant for portable drum type floor sanders used with sand paper sheets to achieve commercial success using a hook and loop fastener system such as a Velcro® brand material to secure a sand paper blank to a fixed diameter drum surface where a joint in the sheet must be exposed to some extent on the drum surface. The reasons why can be readily deduced by one skilled in the art: rotational speed, machine weight, inherent resistant in the abrading motion, exposed leading edge of the sandpaper blank at a joint the drum, effects of the resulting high heat, peeling and shear pressure on the fastening materials, and cost. It has been tried without success by others.
It can be further stated as a generalization that some 30% of floor sander rentals are for use on floor surfaces than can be characterized as rough, such as by having excessive holes, missing or irregular boards, elevated nail heads, and/or other surface irregularities that increase the likelihood of tearing or otherwise damaging the sanding blanks or the drum surface of a floor sander. For this reason, it would be useful to provide a floor sander configured for more easily removing and replacing sanding blanks with correct alignment on the drum, and for easily repairing the drum surface of the sanding drum when necessary.